Published in Physical Review Letters, Volume 56, Issue 7, February 17, 1986, pages 777-779.
Copyright © 1986 American Physical Society. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Physical Society. The following article appeared in Physical Review Letters and may be found at http://dx.doi.org/10.1103/PhysRevLett.56.777.
NOTE: At the time of publication, the author Richard B. Frankel was not yet affiliated with Cal Poly.
The influence of charge-carrier concentration on the magnetic properties of the semimagnetic semiconductor [(PbTe)1-x(SnTe)x]1-y[MnTe] y (x=0.72, y=0.03) is reported. Magnetization, magnetic susceptibility, and specific heat have been measured. For carrier concentrations below p=3 x 1020 cm-3 the alloy is paramagnetic. For p≥3 x 1020 cm-3 an abrupt transition to a ferromagnetic phase is observed at helium temperatures. The ferromagnetic transition temperature increases with increasing p. This is the first demonstration of the effect of carrier concentration on the magnetic properties of semimagnetic semiconductors.